1. Field of the Invention
The present invention relates to a slitter in which a plurality of slitter heads are arranged along and positionally adjustably in a width direction perpendicular to a conveyance direction of a corrugated paperboard, wherein each of the slitter heads comprises a drive motor and a circular slitter blade configured to be independently rotated by the drive motor.
2. Description of the Related Art
Heretofore, there have been proposed various configurations for a type of slitter in which a plurality of slitter heads are arranged along and positionally adjustably in a width direction. For example, a slitter described in the following Patent Document 1 comprises: a plurality of slitter heads; a measurement unit for measuring respective radii of a plurality of slitter blades each comprised in a respective one of the slitter heads; and a head control unit for calculating respective wear amounts of the slitter blades based on the measured radii, and adjusting respective engagement amount between corresponding ones of the slitter blades and a plurality of slitter blade receiving members, according to the wear amounts. Each of the slitter heads further comprises a drive motor for rotating the slitter blades. The slitter described in the Patent Document 1 is capable of adjusting respective engagement amounts between corresponding ones of the slitter blades and the slitter blade receiving members, thereby making it possible to stably cut a corrugated paperboard.
A slitter described in the following Patent Document 2 comprises: a plurality of slitter heads; one drive motor for driving a plurality of slitter blades each comprised in a respective one of the slitter heads; and a motor control unit for variably controlling a speed of the drive motor. The motor control unit is configured to control a rotational speed of the drive motor, according to a speed command selected based on a type of corrugated paperboard, properties of raw paperboard, a type of flute, ambient temperature and ambient humidity which are input through an external input device. Based on this variable speed control of the drive motor, the slitter described in the Patent Document 2 makes it possible to maintain sharpness of a cut edge of a corrugated paperboard without occurrence of any irregular cut edge.